You were warned about bugs, incomplete game and was not promised full release in a year. You bought it anyways.
I think they are simply more vary of telling anything because of their experience before EA release. They told us too many promises which they couldn't do due to unforeseen issues they encountered, which caused everyone to become frustrated, for example when they announced that they might be finishing game in "2017", or announcing game's development itself, they were all rushed without too much consideration. Constant delays only made people more frustrated rather than silence would have.
It's probably because garrisons are very small so it takes little time to siege down a city or a castle. I mean usual Army (collection of vassals) consists of at least 600 troops while garrisons usually consist of 300 troops while castles only have like 150..
Red dead redemption also had already good engine to work with, MB had to create a new engine from scratch multiple years into development after they realized old engine won't be sufficient. Even then I own red dead redemption and it's got plenty of bugs too.. I like the core of game, it does lack some quality of life stuff like following parties, item tiers like rusty or masterwork, quests and I could go on for quite a while, but potential is here, let's hope TW makes it amazing.